1. Technical Field
The present disclosure relates to a touch panel; in particular, to a noise compensating touch panel and a touch device thereof.
2. Description of Related Art
In recent years touch panel applications have been developed rapidly, as well as being utilized commonly in, for instance, ATMs, point-of-sale (POS) terminals and household automation control and management systems. Touch panels are even being used extensively in portable electronic devices such as tablet computers and smartphones, etc. A touch panel provides an intuitive input scheme that brings the conventional input interface to a more approachable level. The demand for HMI (human-machine interface) applications has therefore shown rapid growth.
According to the physical principle deployed to detect a touch point, a touch panel can be classified as resistive or capacitive. For a resistive touch panel, voltage is generated when the resistive touch panel is touched by a finger or a stylus. A capacitive touch panel is operated according to a finger contacting the touch panel for absorbing a very small current. The capacitive touch panel can be further classified as surface capacitive or projected capacitive. The projected capacitive touch panels attract industry attention due to its multi-touch capability. If a projected capacitive touch panel is integrated with a LCD to form an in-cell multi-touch panel, or a projected capacitive touch panel is integrated with an upper/lower surface of a panel color filter to form an on-cell multi-touch panel, thinness of the original panel can also be maintained. ITO (Indium Tin Oxide) is commonly used in TFT-LCD (thin-film-transistor liquid-crystal display) for holding electric charges. By reversely operating the same principle, such ITO can also be utilized as a detector, for achieving high-density detection. However, since a thin-film transistor in a TFT-LCD causes significant noise, the accuracy of capacitive sensing is especially important under the effect of such noise.